(1) Field of the Invention
The present invention relates to a novel construction for a ballast system for an underwater vehicle. More particularly, the invention relates to an encapsulated ballast weight releasable via a spring loaded bolt held in spring tension by a lanyard pin and linear actuator.
(2) Description of the Prior Art
It is often desirable to allow an underwater vehicle to trim its buoyancy as close as possible to a neutral buoyancy while running its mission. It is often difficult to provide controllability, safety and ease of slow-speed maneuvers by trimming an underwater vehicle by means other than a ballast weight system. By carrying a releasable ballast weight, the vehicle may discard the ballast weight thereby becoming positively buoyant and becoming capable of floating to the surface of the water. After an underwater mission has been completed and the ballast weight discarded, the buoyant vehicle becomes more easily recoverable.
Prior ballast weight systems have used explosive-type release mechanisms, such as squibs and explosive bolts. Although relatively safe, explosive bolts present a danger to personnel working with the underwater vehicle prior to its launch as well as during and after its recovery if an unexploded bolt is still present.